As the display technologies develop, light-emitting diodes have been widely applied to display technologies, for example, an Active-matrix organic light-emitting diode (AMOLED) is an example thereof. A control method thereof may be using a driving-transistor to provide current to drive a light-emitting diode to emit light. However, when a test is performed on displaying chess grids with alternate black and white grids, an Image Retention phenomenon will be occurred. For example, when a pixel turns from the gray scale brightness 0 (black) to the gray scale brightness 64 (gray), the brightness of the next image time will be excessively high, and the expected brightness may be achieved till the next image time. Besides, in high-speed applications, in a conversion process from a black image to an image of any gray scale, the expected gray scale brightness may be achieved generally by charging twice. This phenomenon may cause ghost image generated at an image intersection when the black image is turned to an image of any gray scale, so that the image quality of the high-speed display is poor. The unexpected image retention phenomenon is caused by charges aggregating at a channel of a driving-transistor.